Explosive-engine.



No.- 669,416. Patented Mar. 5, |90l.

U. B. JOHNSON.

EXPLDSIVE E NGINE.

(Applicaciun filed sept. 24, 1900.) (No Model.) v 2 Sheets-Sheet l No.669,4l6. Patented Mar. 5, lsol.

o. B. JoHNsoN.

EXPLQSIVE ENGINE.

(Applicntion ledept. 24, 1900.)

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n UNTTED STATES PATENT OFFICE.

ORVILLE B. JOHNSON, OF TYNGSBORO, MASSACHUSETTS.

EXPLOSIVE`ENGINE.

SPECIFICATION forming part of Letters Patent No. 669,416, dated March 5,1901.

Application filed September 24, 1900. Serial No. 30,949. (No model.)

fo (LEZ whom it may concern: I

Be it known that I, ORVILLE B. JOHNSON, of Tyngsboro, in the county ofMiddlesex and State'of Massachusetts, have invented certain new anduseful Improvements in Explosive- Engines, of which the following is aspecification.

This invention relates to engines driven by the heat produced by theexplosion of a mixture of gas or hydrocarbon vapor with air. Suchengines often give trouble in running, owing to the difculty orpractically the impossibility of completely expelling the waste gasesformed by the combustion of the mixture in the cylinder. These wastegases remain in the clearance-space of the cylinder, mixing with andthus vitiating each fresh charge of gas and air and sometimes envelopingthe ignition device so thickly that the charge fails to ignite properlyand the engine is caused to run unevenly.

The object of my invention is to provide a means capable of applicationto any explosion-engine making four strokes of the piston in each cycle,whereby the piston may be forced quite to the head end of the cylinderduring the exhaust-stroke, thus completely expelling the products ofcombustion, while on the compression-stroke the piston stops short ofthe end of the cylinder, leaving a clearance-space, in which iscontained the compressed charge. n

The invention consistsin means hereinafter described by which the travelof the piston may be varied on different strokes, the wristpin beingmeanwhile always distant from the crank-pin by the same amount.

In the accompanying drawings, Figure l represents a longitudinal sectionof an explosion-engine,showing the device embodying my invention, thepiston being in mid-stroke while moving toward the head end of thecylinder. Figs. 2 and 3 represent two elevations of the coupling memberwhich connects the piston with the connecting-rod and which constitutesa part of the means for varying the position of the piston relatively tothe connecting-rod. Figs. i and 5 represent two elevations of a disk orfitting which is secured in the piston and against the nat bearing-faceof which the curved bearing-face of the cou pling member rests. Fig. 6represents a View similar to Fig. 1, showing the piston at the end ofthe compression-stroke ready to be impelled forward by the explosion ofthe charge. Fig. 7 represents a similar View showing the piston at theend of the stroke during which the waste gases are expelled.

The same reference characters designatev the same parts in all thefigures.

Referring to the drawings, the trunk-piston 1, reciprocating in thecylinder 2, drives the shaft 3 through the crank 4 and connectingrod 5.The connecting-rod is yieldingly secured to the piston in such mannerthat the distance between the piston andthe crank-pin 16 may be variableby a coupling mem ber next described and a springcoperating therewith.The said coupling member, as here shown, consists of two web-pieces 14,connected by acylindrical piece 7, to which the connectingrod is jointedand which takes the place of the wrist-pin-in the ordinary form ofengine. On the outer surface of the webs 14 are formed rocker members 9,the curved faces 17 of which bear against the flat outer face of a thickdiskor fitting 13, while the webs 14 project into a depression 15,formed in the said fitting. The fitting is firmly fixed by suitablemeans within a cavity or recess in lthe piston 2, or if theconnecting-rod is held by a cross-head the fitting may be fastened tothecross-head. The coupling member is held in operative position by arod 10, one end of which is secured to the outer portion of the couplingmember by a pin or by trunnions projecting through holes 8 in the websof the coupling member, while the other end is attached to a head orbearing 12, which is forced away from the fitting 13 by a spiral spring11, which abuts against the inner surface of the tting 13. The curvedbearingface of the coupling member is thus pressed against the flatbearing-face of the piston by a force equal to the power of thespring,which may be any desired amount. The coupling member is held inplace vertically by a retainer 18, secured to the disk 13 or to thetrunk of the piston by suitable means, the upper surface of the retainer18 having the shape of the curve traversed by the lower ends of therocker members 9, so that the IOO ends of the members 9 are always incontact with the piece 18 and the coupling member is prevented fromslipping down out ot' place.

When the piston is acted on by no external force greater than that offriction with the cylinder-walls, the spring 1l expands until the partsare in equilibrium, as is shown in Fig. l, the most prominent portion ofthe curved bearing-face 17 being then in contact with the flatbearing-face of the fitting 13. Suppose that the piston moves from theposition shown in Fig. 1, so as to compress the mixture of gas and airin the cylinder. As the piston moves toward the end of the cylinder thepressure constantly increases until it becomes so great that the springis no longer able to maintain the parts in the position shown in Fig. l.When this point is reached, the force acting along the connecting-rodinclines the coupling member, so that the line of contact between thecurved and fiat bearing-face advances upward. This motion of thecoupling member pulls the rod 10 and head l2 attached to it against thepressure of the spring, compressingthe latter. This action continuesuntil the crank reaches the deadpoint, when the compression is at themaximum and the parts are in the position shown in Fig. 6. The point ofcontact between the curved and fiat bearing-faces is then approximatelyon the line of thrust exerted by the connecting-rod, the exact positionof the point of contact depending on the amount of the mixture in thecylinder, for if the gas and air had been admitted during a portion onlyof the Filling stroke of the engine the space at the end of the cylinderrequired by the mixture at the same pressure of compression would beless than that required by the amount of the mixture drawn in throughoutthe entire stroke. The force of the spring would then move the pistonfarther into the cylinder and the point of contact would be somewhatlower than as shown. When the explosion occurs, if the point of contactbetween the curved and fiat bearing-faces is eX- actly on the line ofthrust of the connectingrod the piston and connecting-rod move as a unitand there is no relative motion between them; but if the point ot'contact is not on the line of thrust the piston moves toward theconnecting-rod before the latter starts until the coupling member isinclined, so that the position of the point of contact is as specified,when the piston and connecting -rod move onward as though rigidlyconnected in the ordinary way. rlhere is no tendency, except inertia ofthe coupling member, to cause the point of cont-act to move beyond theposition specified, for that is the position of equilibrium of thepiston and coupling member when under pressure, and the same force whichmoves the coupling member into that position causes it to return whenthe point of contact has advanced beyond the line of thrust of theconnecting-rod, and, in addition, the

farther the point of contact advances the greater is the leverage onwhich the spring acts to bring it back.

The spring sustains no portion of the sudden pressure caused by theexplosion, as the pressure is transmitted from the piston through thecoupling member to the connecting-rod, and these parts are all in rigidconnection when in the position they occupy at the time of explosion,except when the point of contact is not within the line of thrust, andthen the spring undergoes buta slightly-increased degree of compression.Thus the spring is not subject to shock while under stress, and as it isnever strained unduly there is nothing to cause it to lose its efciency.

When the piston makes the return stroke after the explosion, it expelsthe products of combustion or waste gases. The piston keeps the sameposition relative to the connect-ingrod as that shown in Fig. 1 untilthe crank approaches the dead-poii1t,when the connecting-rod graduallycomes to rest and starts in the opposite direction. The inertia of thepiston, however, causes it to continue its motion after theconnecting-rod has stopped,and the moving parts then assume the positionshown in Fig. 7. Motion ot' the piston away from the connecting-rodcauses the curved bearing-face of the coupling member to roll downwardon the flat bearing-face of the piston in consequence of the pull of theconnecting-rod onihe pin away from the piston. This motion of thecoupling member, as well as the upward rolling movement,exerts a pull onthe rod 10, compressing the spring and increasing the leverage withwhich the spring acts on the coupling member to return it to theposition of equilibrium, since the point of contact between the curvedand iiat bearing-surfaces acts as the fulcruin. Thus the motion of thepiston away from the connectin g-rod, as well as motion toward it, isresisted by the spring. As soon as the force exerted by the springbecomes as great as the force due to the kinetic energy of the pistonthe piston is brought to rest and begins to follow the connecting-rod onthe second outward stroke of the cycle, the stroke during which thecylinder is filled with a 'fresh mixture. The spring is designed ofsufficient power to allow the piston to approach as near the head of thecylinder as possible without striking it.

It is evident that this invention provides a simple and efficient meansfor clearing the cylinder of waste gases after each explosion, and inaddition it provides a variable clearance space which contains thecompressed charge at substantially the same pressure, which can beregulated by the power of the whether the charge be the full one orreduced in quantity. To the Y best of my knowledge this result is notattained by any form of engine now in use.

Having thus explained the nature of my invention and described a way ofconstruct- IOO IIO

ISO

ing and using the same, though Without attempting to set forth all ofthe forms in which it may be made or all of the modes of its use, what Iclaim, and desire to secure by Letters Patent, is

l. An explosive-engine comprisinga reciprocating member, such as apiston, having a bearing-face, a coupling member jointed to theconnecting-rod or part which receives motion from the piston and adaptedto stand at different angles with the connecting-rod, said couplingmember having a complementai bearing-face, and a yielding connectionbetween the'two members, whereby a yielding cont-act is maintainedbetween the said bearing-faces, one' of said faces being curved.

2. An explosive-engine comprisinga reciprocating member, such as apiston, having a bearing-face, a coupling member jointed to theconnectingrod or part which receives motion from the piston and adaptedto stand at different angles with the connectingrod, said couplingmemberhavingacomplemental bearing-face, a rod jointed to the outerportion ot' said coupling member, and a spring interposed between abearing on said rod and a bearing on vthe piston, whereby a yieldingcontact is maintained between the said bearing-faces, one of said facesbeing curved,

3. An explosive-engine comprising a piston having a flat bearing-face, acoupling member jointed to the connecting-rod which receives motion fromthe piston and having a curved bearing-face resting against the Iiatbearing-face of the piston, a rod jointed to the outer portion of thecoupling member, and a spring interposed between a bearing on the outerportion of the rod and a bearing on the piston, whereby a yieldingcontact is maintained between the said bearing-faces.

4. An explosive-engine comprising a recessed piston, a fitting seated inthe recess of the piston and having a dat bearing-face, a couplingmember jointed to the connectingrod which receives motion from thepiston and havinga curved bearing-face resting against the said flatbearing-face, a rod jointed to the outer portion of the coupling memberand extending through the said fitting into a cavity between the ttingand the head of the piston, a bearing-head jointed to the outer portionof the rod, and a spring interposed between the said bearing-head andthe tting.

5. An explosive-engine comprisingapist-on having a at bearing-face, acoupling member jointed to the connecting-rod which receives motion fromthe piston and having a curved bearing-face resting against the fiatbearing-face of the piston, a rod jointed to vthe outer portion o'f thecoupling member, a

spring interposed between a bearing on the outer portion of the rod anda bearing on the piston, whereby a yielding contact is maintainedbetween the said bearing-faces, and a coupling-retainer on the pistonhaving a segmental retaining-face engaging a portion of the coupling.

In testimony whereof I have affixed my signature in presence of twowitnesses.

ORVILLE B. JOHNSON.

Witnesses:

C. F. BROWN, A. D. HARRISON.

